Method and apparatus for use in driving piles



April 18, 1967 G. E. MAYHALL 3,314,241

METHOD AND APPARATUS FOR USE IN DRIVING FILES 4 Sheets-Sheet 1 Filed Dec. 21, 1964 MUD LINE FOR MATION I NVENTOR.

GEORGE E M AY H ALL HARD PACKED SAND WATER HOSES NEW S ECTION- ATTOR NEY.

April 7 ca. E. MAYHALL 3,

METHOD AND APPARATUS FOR USE IN DRIVING PILES Filed Dec. 21, 1964 4 Sheets-Sheet 2 L J INVENTOR.

GEORGE E- MAYHALL,

W MLMU ATTORNEY.

G. E. MAYHALL 4 Sheets-Sheet 15 AND APPARATUS FOR USE IN DRIVING PILES April 18, 1967 METHOD Filed Dec. 21, 1964 DRIVING HEAD I8 v @iillll'" WATER ""1 LINE MG FLOATI AIR LINE PLATE 36\ comgcnou 42 D b 35 \\PILING SEAL RING/ N ew sac-non OF ,H

PILING\ l4b V PILI Ms E INVENTOR.

W G EOR G E E. MAY HALL, iii? j ATTO RNEY.

FIG.4A.

April 1967 G. E. MAYHALL 3,314,241

METHOD AND APPARATUS FOR USE IN DRIVING FILES Filed Dec. 21, 1964 4 Sheets-Sheet 4 FIG; 7.

INVENTOR.

GEORGE E. MAYHALL,

ATTORNEY.

United States Patent Office 3,314,241 Patented Apr. 18, 1967 3,314,241 METHOD AND APPARATUS FOR USE IN DRIVING PELES George E. Mayhall, New Orleans, La., assignor, by mesne assignments, to Esso Production and Research Company, Houston, Tex., a corporation of Delaware Filed Dec. 21, 1964, Ser. No. 420,071 10 Claims. (Cl. 6153.5)

The present invention generally concerns the construction of drilling platforms and, in particular, it concerns an improved method of driving piles in forming foundations for drilling platforms. The invention also concerns apparatus for use in driving piles in accordance with this method.

When driving piles by ordinary hammer means, especially piles used to carry offshore drilling structures, adequate pile penetrations cannot be achieved in dense sands because of the great buildup of end bearing on the piles in the sand formation. Pile driving in such sands often results in premature refusal, particularly for tension or holddown requirements.

The pile driving method to be described herein overcomes disadvantages inherent in ordinary pile driving techniques. It achieves deep penetrations of the piles into dense sand formations with a minimum of pile driving difficulty.

In application Ser. No. 352,923, filed Mar. 18, 1964, by Arthur L. Guy, entitled, Method and Apparatus for Driving Piles, nowPatent No. 3,289,420, an operation is described in which pilings such as steel tubings or cylinders are driven with a hammer in a conventional way while water is pumped and jetted simultaneously into the sand in a closed, hydrostatic system. In the practice of the Guy operation, the resistance to pile penetration is reduced and it is possible to drive the pile through dense, thick sand strata. However, when driving the pile and pumping of water are halted for a prolonged period of time, it is often difficult or impossible to resume movement of the pile. Each time a new section of pile to be driven is added to the previously driven pile sections, it must be welded to the driving head to provide the closed hydrostatic system and a lengthy or prolonged period of time is consumed in welding these members to each other.

The present invention avoids welding the driving head to the new pile section to be added by releasably latching these members together and by using a pack-off assembly as a substitute for the weld seal. In this manner, each piling is made pressure tight at the connection between the driving head and the new section of piling to form a closed hydrostatic system. The method for driving piles according to the present invention uses a driving head adapted to be removably connected to the upper end of the uppermost pile section and containing a chamber; a conduit extending from said chamber into said pile section when said driving head and pile section are engaged; and sealing means arranged on said conduit adapted to seal off the annulus between said conduit and said pile section upon the application of fluid pressure to said sealing means below said sealing means and comprises the steps of connecting said driving head to the upper end of said pile section; pumping hydraulic fluid into said chamber and through said conduit and applying fluid pressure to said sealing means below said sealing means to seal off the annulus between said conduit and said pile section; and then driving said piling with said driving means while pumping fluid into said chamber and through said conduit.

A primary object of the invention is to substantially decrease pile driving time. Another important object of the invention is to make penetration of the sand formations easier. A further object of the invention is to provide a more eflicient system for driving piles.

The above and other objects and advantages of the invention will be apparent from the following, more detailed description of the invention when taken with the drawings in which:

FIG. 1 is a side elevation of apparatus embodying the invention and illustrating one manner of driving piles in offshore locations;

FIGS. 2 to 4 are side elevations of a pile to be driven into the underlying sand and illustrating positioning of a jet assembly and its action within the pile in accordance with the method of the Guy application;

FIG. 4A is a side elevation, partly in section, of the driving head and packer assembly connected to a section of pile to be driven in accordance with the invention;

FIG. 5 is an enlarged view of the packer assembly arranged in the section of pile to be driven;

FIG. 6 is a view taken along lines 66 of FIG. 5; and

FIG. 7 is a view similar to FIG. 5 showing a modification of the packer assembly.

Referring to the drawings in more detail, in FIG. 1 is shown a barge 10 on which is mounted a platform 11 and a crane 12 from which is suspended a steam hammer 13 used to drive piles 14 into the dense sand formation 15. A zone of less dense sand or mud 16 is located above formation 16 and below water 17. One pile has been driven through to refusal and the other pile consisting of initial pile sections 14a and a new pile section 14b are being driven into sand formation by means of a driving head 18 on which is mounted steam hammer 13. The sections of pile are welded together as indicated at 19. In the manner of operation in the Guy application, the driving head was also welded to the upper end of the new section of piling 14b. However, the present invention eliminates the need to weld the driving head to the new section of pile. A seal is formed without a weld which saves considerable time in making up the joint.

FIGS. 2 to 4 show the pile section 14:: in position for penetration into sand formation 15. In FIG. 3 a jet line assembly 20 is shown arranged in pile section 14a. Assembly 29 includes a hollow, tubular jet line member 21 provided with a connection 22 to which a hose 22a is attached at its upper end and which contains perforations 23 adajacent its lower end. Centralizers 24 are arranged along its length to maintain tube 21 upright and centrally positioned within pipe section 14a. Cable loops 25 are provided adjacent the upper end of tube 21 to aid in placing it within and removing it from pile sections 14. Hose 22a feeds water to tube 21 from an external surface source of supply. The water jets through perforations 23 and aids in washing assembly 20 through mud 16 (see FIG. 3). Once assembly 20 reaches sand formation 15, hose 22a is removed from connection 22 as illustrated in FIG. 4. This figure also shows the lower end of new pile section 1412 welded to the top of pile section 14a. Tube 21 penetrates formation 15 as water within the pile sections 14 passes into opening 22 through tube 21 and jets from perforations 23.

As shown in FIG. 4A, driving head 18 has welded to it a pack-off assembly 34 which includes a tubular steel conduit 35 extending through a partition 36 in the lower end of driving head 18. Radially extending reinforcing plates 37 are welded to conduit 35 and to the lower end of driving head 18. The sealing elements of pack-off assembly 34 include a fixed plate 38, welded to reinforcing plates 37 and conduit 35, and provided with weep holes 39 (see FIG. 5). Conduit 35' is rigidly installed in the center of plate 38 which has an outside diameter slightly less than the inside diameter of the piling 14b as seen in FIGS. 4A and 5. The seam between the outside of and outer circumferences, respectively, of plate 38.

conduit 35 and plate 38 is welded pressure tight. Two seal rings 40 and 41 are arranged below and on the inner A hollow, floating plate 42 of the same diameter as plate 38 and provided with a center opening having the same clearance around conduit 35 as plate 38 is arranged below seal rings 40 and 41. Stabbing guides or plates 43 are welded to conduit 35 below plate 42. These plates act as stops for traveling plate 42 and prevent it from falling from conduit 35. A padeye 44, connected to head 18, and pins 45 connected to piling section 141), are arranged to secure driving head 18 to piling section 1411. Instead of the pin connection (45) to attach the driving head to the new section of pile 14b, cable straps may be used.

The modified packer assembly 34, shown in FIG. 7, is similar to the assembly shown in FIG. and functions in the same manner. The numerals carrying the markings designate equivalent components of the packer assemblies. The floating plate 42', as shown in FIG. 7, is a plate member with an annular recess provided in the upper face thereof. The upwardly extending annular shoulders are formed to contact the seal rings 40' and 41', simultaneously.

Referring particularly to FIG. 4A, driving head 18 is connected by means of the padeye-pin arrangement 44- 45 to pile section 1412. The lower end of this pile section is welded to the driven pile section 14a after which hydraulic fluid is pumped through connections 32 arranged on driving head 18 and into the pile sections through conduit 35. When pile section 14b fills with water below assembly 34 hydraulic pressure acts on the underside of traveling plate 42 to force it upwardly, Upward force on plate 42 compacts seal rings 40, 41 against plate 38 and the inner wall of pile section 1412 and the outer wall of conduit 35. Water which might have been trapped between floating plate 42 and fixed plate 38 bleeds off through the small holes 39 in plate 38 to above the assembly and to the atmosphere. Compacted seal rings 40, 41 effect a tight seal to all fluid pressure in the pile sections. A small amount of leakage around seal rings 40, 41 occurs when fluid pressure is first applied and until assembly 34 seals the interior of the pile sections at approximately 40 p.s.i.g. The pile sections are then driven 'by steam hammer 13 through driving head 18 into the sand formations. Resistance to driving of the pile is reduced by the jetting action of the water through the jet line assembly 21 as explained in the Guy application, supra. Jet line assembly 21 was arranged in the lower pile sections prior to connecting driving head 18 to the pile section to be driven. washed to the sand formation by pumping water through connections 32 and conduit 35.

During the pile driving operation, driving head 18 may be supplied with air through connection 33. The column of air within driving head 18 remains trapped so that the energy of driving is expended to the walls of the pile and not against the water column inside the pile. Additional air may be supplied through connection 33 in the event air is lost or dissipated through the water.

Additional sections of pile are added, when needed, through the procedure described above. When each new section of pile has been driven to refusal, pumping of water into driving head 18 is discontinued. Also, air pressure within driving head 18 is released. When the pressure is released at the pump or at some other point outside of the piling, the floating plate 42 drops down to stop 43 and unseals assembly 34. Driving head 18 is then disconnected from pile section 14b and it, together with assembly 44, is removed from the upper end of this pile section.

Having fully described the nature, method, objects, and advantages of my invention, I claim:

1. A method for driving tubular, hollow piles comprising the steps of:

The jet line assembly may be 4- connecting a pile driving head to the top of a new section of tubular, hollow piling to be driven;

welding the lower end of said new section of piling to the top of a driven section of tubular, hollow piling;

said pile driving head containing a chamber and having connected to its lower end a conduit extending into said new section of piling and on which is arranged sealing means adapted to seal off the annulus between said conduit and the interior wall of said new pile section upon application of fluid pressure to the underside of said sealing means;

supp-lying fluid to the underside of said sealing means through said chamber and said conduit to cause said sealing means to expand and seal off the annulus between said conduit and the interior wall of said new pile section and thereby form a closed, hydrostatic system; and

then driving said piling into said formation with said driving head while supplying fluid to the interior of said piling through said chamber and said conduit.

2. A method as recited in claim 1 including arranging a jet line assembly comprising a tube provided with an opening at its upper end and perforations at its lower end in said piling prior to connecting said pile driving head to the top of said new section of piling and welding said new section of piling to said driven section of piling.

3. A method for driving tubular, hollow piles using a pile driving head adapted to be removably connected to the upper end of the uppermost pile section and containing a chamber, a conduit extending from said chamber into said pile section when said driving head and pile section are engaged, and sealing means arranged on said conduit adapted to seal off the annulus between said conduit and said pile section upon the application of fluid pressure to said sealing means below said sealing means which comprises the steps or":

connecting said driving head to the upper end of said pile section;

pumping hydraulic fluid into said chamber and through said conduit and applying fluid pressure to said sealing means below said sealing means to seal ofl the annulus between said conduit and said pile section; and

then driving said piling with said driving head while pumping fluid into said chamber and'through said conduit.

4. A method as recited in claim 3 including:

arranging a jet line assembly comprising a tube provided with an opening at its upper end and perforations at its lower end in said piling;

washing said jet line assembly to the lower end of the piling with water; and

then driving the piling into said formation with said driving means while simultaneously jetting fluid under pressure into said formation through said jet line assembly.

5. Apparatus for use in driving piles comprising:

a pile driving head adapted to be removably connected to the upper end of a section of pile and provided with a chamber;

a conduit extending from said chamber through the lower end of said driving head fluidly communicac ing said chamber and said section of pile when said driving head is attached thereto;

a fixed plate secured to said conduit intermediate the ends thereof, said conduit extending through said fixed plate;

. seal means arranged about the inner and outer peripheries of said fixed plate;

a floating plate slidably arranged on said conduit and axially aligned with said fixed plate and arranged below said seal means adapted to move upwardly and engage and expand said seal means to seal off the annulus between said conduit and said pile section upon application of fluid pressure below said floating plate;

stop means arranged on said conduit adapted to retain said floating plate on said conduit; and

means connected to said chamber adapted to supply fiuid thereto.

6. Apparatus as recited in claim 5 in which said fixed and floating plates have circular configurations and said seal means comprises seal n'ngs arranged about the inner and outer peripheries of said fixed plate.

7. Apparatus as recited in claim 6 in which said floating plate is hollow.

8. Apparatus as recited in claim 7 in which said fixed plate is provided with an opening therethrou gh to permit release of fluid trapped between said fixed plate and said floating plate.

9. Apparatus as recited in claim 6 in which said float- References Cited by the Examiner UNITED STATES PATENTS 911,971 2/1909 Gilbreth 61-53.7-4 955,729 4/1910 Welsh 6153.74 3,215,201 11/1965 Lacy et al 7567 X CHARLES E. OCONNELL, Primary Examiner.

JACOB SHAPIRO, Examiner. 

1. A METHOD FOR DRIVING TUBULAR, HOLLOW PILES COMPRISING THE STEPS OF; CONNECTING A PILE DIRIVING HEAD TO THE TOP OF A NEW SECTION OF TUBULAR, HOLLOW PILING TO BE DRIVEN; WELDING THE LOWER END OF SAID NEW SECTION OF PILING TO THE TOP OF A DRIVEN SECTION OF TUBULAR, HOLLOW PILING; SAID PILE DRIVING HEAD CONTAINING A CHAMBER AND HAVING CONNECTED TO ITS LOWER END A CONDUIT EXTENDING INTO SAID NEW SECTION OF PILING AND ON WHICH IS ARRANGED SEALING MEANS ADAPTED TO SEAL OFF THE ANNULUS BETWEEN SAID CONDUIT AND THE INTERIOR WALL OF SAID NEW PILE SECTION UPON APPLICATION OF FLUID PRESSURE TO THE UNDERSIDE OF SAID SEALING MEANS; SUPPLYING FLUID TO THE UNDERSIDE OF SAID SEALING MEANS THROUGH SAID CHAMBER AND SAID CONDUIT TO CAUSE SAID SEALING MEANS TO EXPAND AND SEAL OFF THE ANNULUS BETWEEN SAID CONDUIT AND THE INTERIOR WALL OF SAID NEW PILE SECTION AND THEREBY FROM A CLOSED, HYDROSTATIC SYSTEM; AND THEN DRIVING SAID PILING INTO SAID FORMATION WITH SAID DRIVING HEAD WHILE SUPPLYING FLUID TO THE INTERIOR OF SAID PILING THROUGH SAID CHAMBER AND SAID CONDUIT. 